分布式系统可靠性研究的问题和挑战

分布式系统中软件可靠性是应用软件的发布者和用户关心的重要问题。针对大规模分布式应用,包括电子政务、电子商务、多媒体服务和端到端的自动化解决方案,已经产生了各种各样的模型来评价或预测其可靠性,但是这些系统的可靠性问题依然存在。相反,为了确保分布式系统的可靠性,要求在预测或评价整个系统可靠性之前,检查与企业分布式应用相关的每一个单个构件或因素的可靠性,且实现透明的错误检测和错误恢复机制为用户提供无缝交互。因此,文章从检查单个构件可靠性的角度,提出了在分布式系统上运行的应用软件可靠性的问题和挑战。     

大型空分制氧站DCS调试技术

以宝钢集团浦钢60000 Nm3/h的大型空分制氧站DCS调试为基础,结合以往大型空分制氧站DCS调试经验,探讨了大型空分制氧站DCS调试的特点、施工组织、调试工艺及方法,并对控制回路试验、离心式压缩机防喘振控制组态、压缩机起停及控制逻辑、紧急停车及重要安全回路调试、组态临时变更管理等重点、难点及关键环节的调试技术进行了详细的总结、说明,旨在为其他同类工程提供参考与借鉴.     

基于Host Link FINS协议的PLC远程通信

以欧姆龙公司CP1H型号的PLC为应用背景,设计了基于Host Link FINS协议的PLC设备远程监控系统.该文提出了基于串口的远程通信方案,并且详细分析了Host Link FINS协议的结构和指令格式,用MFC实现了监控软件的设计,完成监控软件与欧姆龙PLC的数据通信功能,实现监控软件对PLC的远程监控.经过现场的测试和运行,该监控系统稳定可靠,性能较高.     

DCS在酸相法氯化聚乙烯生产中的应用

把DCS应用于酸法生产CPE中，描述了DCS的硬件配制，生产中的控制要点及自控方案，在工业化生产中取得了良好效果。     

Analysis of a large number of Markov chains competing for transitions

We consider the behaviour of a stochastic system composed of several identically distributed, but non independent, discrete-time absorbing Markov chains competing at each instant for a transition. The competition consists in determining at each instant, using a given probability distribution, the only Markov chain allowed to make a transition. We analyse the first time at which one of the Markov chains reaches its absorbing state. When the number of Markov chains goes to infinity, we analyse the asymptotic behaviour of the system for an arbitrary probability mass function governing the competition. We give conditions that ensure the existence of the asymptotic distribution and we show how these results apply to cluster-based distributed storage when the competition is handled using a geometric distribution.     

Stability analysis and controller synthesis for discrete uncertain singular fuzzy systems with distinct difference matrices in the rules

This paper mainly studies an extended discrete singular fuzzy model incorporating the multiple difference matrices in the rules and discusses its stability and design issues. By embracing additional algebraic constraint, traditional discrete Takagi-Sugeno (T-S) fuzzy model can be extended to a generalised discrete singular Takagi-Sugeno (GDST-S) model with individual difference matrices E_i in the locally singular models, where it can describe a larger class of physical or non-linear systems. Based on the linear matrix inequality (LMI) approach, we focus on deriving some explicit stability and design criteria expressed by the LMIs for the regarded system. Thus, the stability verification and controller synthesis can be performed by the current LMI tools. Finally, some illustrative examples are given to illustrate the effectiveness and validity of the proposed approach.     

State space approximation for general fractional order dynamic systems

Approximations for general fractional order dynamic systems are of much theoretical and practical interest. In this paper, a new approximate method for fractional order integrator is proposed. The poles of the approximate model are unrelated to the order of integrator. This feature shows benefits on extending the algorithm to the systems containing various fractional orders. Then a unified approximate method is derived for general fractional order linear or nonlinear dynamic systems via combining the proposed new method with the distributed frequency model approach. Numerical examples are given to show the wide applicability of our method and to illustrate the acceptable accuracy for approximations as well.     

基于SOAP的企业异构信息系统集成

阐述了SOAP通信协议的构成和实现机制以及与相似协议的比较。基于它的跨平台的能力,将其运用于企业的分布式环境中,实现了异构信息系统间的互操作和跨部门的数据处理,提高企业数据处理的效能,同时为企业异构信息系统集成提供了新的方法。     

微信公众号服务网站在BAE3.0上的设计与实现

介绍了一种在BAE3.0上搭建Java-Tomcat类型的微信公众号服务网站的设计思路,以及使用百度开放云上的应用引擎、MySQL数据库、分布式日志服务和百度云存储等相关资源实现微信公众号服务网站的一般过程。     

帧转移型CCD图像去smear效应研究

作为无快门CCD的固有缺陷,Smear效应严重影响其在遥感成像探测领域的应用。通过对帧转移型CCD成像过程中smear效应产生机理的分析,提出了一种减小甚至消除smear效应的方法,即下传虚拟参考行法。利用该方法对一台成像光谱仪输出信号进行校正,很好地实现了smear效应影响的消除,从而证明该方法的可行性。同时,也证明了下传虚拟参考行法对其他任何类型CCD的适用性。